SAN FRANCISCO: A colossal aircraft capable of launching satellite-toting rockets into space is closer to testing, having been rolled out of a hangar in the desert, its creators said on Wednesday (Thursday in Manila). The project backed by billionaire Microsoft co-founder Paul Allen has been proceeding for about six years and was on track for its first launch demonstration as early as 2019, Stratolaunch Systems Corporation chief executive Jean Floyd said in a blog post. In the weeks and months ahead, Stratolaunch—touted as the biggest airliner ever built—will be testing fuel systems, engines and more on the ground at its air and space port in the Mojave desert, according to Floyd. Support structures were removed from the plane during the past few weeks, allowing it to rest on its 28 wheels for the first time. The Stratolaunch aircraft weighed in at 500,000 pounds (226,796 kilograms) and has the world’s largest plane wingspan, measuring 385 feet (117 meters), according to the company.The aircraft is 238 feet from nose to end, and it is 50 feet from the ground to the tip of its vertical tail.